From https://www.thehindu.com/news/national/over-86-per-cent-of-breakthrough-infections-caused-by-delta-variant-icmr/article35367198.ece (mirror):
A breakthrough infection is a case of illness in which a vaccinated individual becomes sick from the same illness that the vaccine is meant to prevent.
What's the translation of a “breakthrough infection" in French?
Google Translate didn't help.